Dystonia Induced by Gabapentin

OBJECTIVE:To report a case of dystonia as an adverse effect of gabapentin.CASE SUMMARY:A 72-year-old woman was diagnosed with essential tremor and treated with propranolol 120 mg daily. The drug was withdrawn because of bradycardia, and gabapentin was prescribed 3 times a day at escalating doses to reach 2100 mg daily. The woman developed a dystonic reaction involving muscles of the neck and both arms that resolved rapidly after drug withdrawal. She was restarted on gabapentin with slow titration to 1800 mg daily, but the same dystonic reaction appeared, which led to definitive withdrawal of the drug. An objective causality assessment revealed that this adverse effect was highly probable.DISCUSSION:There have been only a few previous reports of gabapentin-induced dystonia. Other movement disorders reported with gabapentin include myoclonus, ataxia, and choreoathetosis. Gabapentin has been used to treat dystonias with variable results.CONCLUSIONS:Although gabapentin is widely used and well tolerated, it ca...